WooSMS Extensions plugins

Customer & Admin SMS Variables extensions

add_action("woosms_extends_variables", function(Extensions\Hook\Variables $variables, Extensions\Database\IDatabase $database)
{
    $result = $database->execute('SELECT `tracking_number` FROM `order` WHERE order_id = "'.$database->escape($variables->get('order_id')).'"');

    if($result->getNumRows())
    {
        $row = $result->getRow();
        $variables->set('tracking_number', $row->tracking_number);
    }

    /** Now you can use in Customer or Admin SMS variable <tracking_number> */

}, 20, 2);

Ready made solutions

woosms-aftership-exntesion - Customer & Admin SMS variables extension https://wordpress.org/plugins/aftership-woocommerce-tracking/

<_aftership_tracking_provider>, <_aftership_tracking_provider_name>, <_aftership_tracking_required_fields>,
<_aftership_tracking_number>, <_aftership_tracking_shipdate>, <_aftership_tracking_postal>,
<_aftership_tracking_account>, <_aftership_tracking_key>, <_aftership_tracking_destination_country>

woosms-wcst-shipping-tracking - Customer & Admin SMS variables extension https://codecanyon.net/item/woocommerce-shipping-tracking/11363158

<_wcst_order_trackno>, <_wcst_track_without_tracking_code>, <_wcst_order_dispatch_date>,
<_wcst_custom_text>, <_wcst_order_trackname>, <_wcst_order_trackurl>, <_wcst_order_track_http_url>

woosms-eupago-multibanco - Customer & Admin SMS variables extension https://wordpress.org/plugins/eupago-for-woocommerce/

<_eupago_multibanco_entidade>, <_eupago_multibanco_referencia>